Kell Brook's sole focus is on a 'mega fight' against Amir Khan or Terence Crawford after he switched his attention away from an appearance on the Anthony Joshua bill.
The British rivals resumed talks for an elusive fight last year, but Khan opted instead to challenge Terence Crawford for the WBO welterweight title, suffering a painful sixth-round stoppage loss after he was unable to recover from a low blow.
Brook was initially due to appear on the undercard of Joshua's US debut against Andy Ruiz Jr in New York on June 1, live on Sky Sports Box Office, although he is now pursuing a fight with Crawford or Khan.
"He's not fighting June 1st," Hearn confirmed to Sky Sports. "He just wants to jump into a mega fight now.
"He wants the Terence Crawford fight; we'll see if the Amir Khan fight can ever materialise. It's still a big fight, it's still a fight people want to see.
"Khan didn't really take a lot of damage in the Crawford fight, apart from one in the nuts, so we'll have to see.
"But Kell wants Crawford, he wants Khan, he wants any major fight and I don't think he can get himself motivated for anything else.
"There hasn't been any conversation since the [Crawford] fight. We're due one this week, so we'll see."